fix: dep conflict

[mjbradford89]

Ran into this issue with vcrpy kevin1024/vcrpy#688 that is also happening on develop https://gitlab.polyswarm.io/externalci/polyswarm-api/-/jobs/237116.

__________________ ERROR collecting test/client_scan_test.py ___________________
/usr/local/lib/python3.7/site-packages/vcr/patch.py:40: in <module>
    _VerifiedHTTPSConnection = cpool.VerifiedHTTPSConnection
E   AttributeError: module 'urllib3.connectionpool' has no attribute 'VerifiedHTTPSConnection'

The easiest fix seems like not using the latest requests package, which uses the newer version of urllib. We use requests in our api, but vcrpy is only used for testing purposes. So I created a separate requirements file. That way we can still use the latest requests package without running into the testing issue.

[mrsarm]

Nice trick!

Still we should subscribe to the issue in vcr, and once fixed in their side just upgrade to the last version, but in the meantime we need this.